Energy Resource Management under the Influence of the Weekend Transition Considering an Intensive use of Electric Vehicles

Energy resource scheduling is becoming increasingly important, as the use of distributed resources is intensified and of massive electric vehicle is envisaged. The present paper proposes a methodology for day-ahead energy resource scheduling for smart grids considering the intensive use of distributed generation and Vehicle-to-Grid (V2G). This method considers that the energy resources are managed by a Virtual Power Player (VPP) which established contracts with their owners. It takes into account these contracts, the users' requirements subjected to the VPP, and several discharge price steps. The full AC power flow calculation included in the model takes into account network constraints. The influence of the successive day requirements on the day-ahead optimal solution is discussed and considered in the proposed model. A case study with a 33-bus distribution network and V2G is used to illustrate the good performance of the proposed method.

Contextual and Environmental Awareness Laboratory for Energy Consumption Management

The recent changes on power systems paradigm requires the active participation of small and medium players in energy management. With an electricity price fluctuation these players must manage the consumption. Lowering costs and ensuring adequate user comfort levels. Demand response can improve the power system management and bring benefits for the small and medium players. The work presented in this paper, which is developed aiming the smart grid context, can also be used in the current power system paradigm. The proposed system is the combination of several fields of research, namely multi-agent systems and artificial neural networks. This system is physically implemented in our laboratories and it is used daily by researchers. The physical implementation gives the system an improvement in the proof of concept, distancing itself from the conventional systems. This paper presents a case study illustrating the simulation of real-time pricing in a laboratory.

Resource Scheduling in Residential Microgrids Considering Energy Selling to External Players

The operation of distribution networks has been facing changes with the implementation of smart grids and microgrids, and the increasing use of distributed generation. The specific case of distribution networks that accommodate residential buildings, small commerce, and distributed generation as the case of storage and PV generation lead to the concept of microgrids, in the cases that the network is able to operate in islanding mode. The microgrid operator in this context is able to manage the consumption and generation resources, also including demand response programs, obtaining profits from selling electricity to the main network. The present paper proposes a methodology for the energy resource scheduling considering power flow issues and the energy buying and selling from/to the main network in each bus of the microgrid. The case study uses a real distribution network with 25 bus, residential and commercial consumers, PV generation, and storage.

Gest��o de Recursos Energ��ticos nas SmartGrids

A sustentabilidade do sistema energ��tico �� crucial para o desenvolvimento econ��mico e social das sociedades presentes e futuras. Para garantir o bom funcionamento dos sistemas de energia actua-se, tipicamente, sobre a produ����o e sobre as redes de transporte e de distribui����o. No entanto, a integra����o crescente de produ����o distribu��da, principalmente nas redes de distribui����o de m��dia e de baixa tens��o, a liberaliza����o dos mercados energ��ticos, o desenvolvimento de mecanismos de armazenamento de energia, o desenvolvimento de sistemas automatizados de controlo de cargas e os avan��os tecnol��gicos das infra-estruturas de comunica����o imp��em o desenvolvimento de novos m��todos de gest��o e controlo dos sistemas de energia. O contributo deste trabalho �� o desenvolvimento de uma metodologia de gest��o de recursos energ��ticos num contexto de SmartGrids, considerando uma entidade designada por VPP que gere um conjunto de instala����es (unidades produtoras, consumidores e unidades de armazenamento) e, em alguns casos, tem ao seu cuidado a gest��o de uma parte da rede el��ctrica. Os m��todos desenvolvidos contemplam a penetra����o intensiva de produ����o distribu��da, o aparecimento de programas de Demand Response e o desenvolvimento de novos sistemas de armazenamento. S��o ainda propostos n��veis de controlo e de tomada de decis��o hierarquizados e geridos por entidades que actuem num ambiente de coopera����o mas tamb��m de concorr��ncia entre si. A metodologia proposta foi desenvolvida recorrendo a t��cnicas determin��sticas, nomeadamente, �� programa����o n��o linear inteira mista, tendo sido consideradas tr��s fun����es objectivo distintas (custos m��nimos, emiss��es m��nimas e cortes de carga m��nimos), originando, posteriormente, uma fun����o objectivo global, o que permitiu determinar os ��ptimos de Pareto. S��o ainda determinados os valores dos custos marginais locais em cada barramento e consideradas as incertezas dos dados de entrada, nomeadamente, produ����o e consumo. Assim, o VPP tem ao seu dispor um conjunto de solu����es que lhe permitir��o tomar decis��es mais fundamentadas e de acordo com o seu perfil de actua����o. S��o apresentados dois casos de estudo. O primeiro utiliza uma rede de distribui����o de 32 barramentos publicada por Baran & Wu. O segundo caso de estudo utiliza uma rede de distribui����o de 114 barramentos adaptada da rede de 123 barramentos do IEEE.

Electricity markets modeling considering complex contracts and aggregators

All over the world, the liberalization of electricity markets, which follows different paradigms, has created new challenges for those involved in this sector. In order to respond to these challenges, electric power systems suffered a significant restructuring in its mode of operation and planning. This restructuring resulted in a considerable increase of the electric sector competitiveness. Particularly, the Ancillary Services (AS) market has been target of constant renovations in its operation mode as it is a targeted market for the trading of services, which have as main objective to ensure the operation of electric power systems with appropriate levels of stability, safety, quality, equity and competitiveness. In this way, with the increasing penetration of distributed energy resources including distributed generation, demand response, storage units and electric vehicles, it is essential to develop new smarter and hierarchical methods of operation of electric power systems. As these resources are mostly connected to the distribution network, it is important to consider the introduction of this kind of resources in AS delivery in order to achieve greater reliability and cost efficiency of electrical power systems operation. The main contribution of this work is the design and development of mechanisms and methodologies of AS market and for energy and AS joint market, considering different management entities of transmission and distribution networks. Several models developed in this work consider the most common AS in the liberalized market environment: Regulation Down; Regulation Up; Spinning Reserve and Non-Spinning Reserve. The presented models consider different rules and ways of operation, such as the division of market by network areas, which allows the congestion management of interconnections between areas; or the ancillary service cascading process, which allows the replacement of AS of superior quality by lower quality of AS, ensuring a better economic performance of the market. A major contribution of this work is the development an innovative methodology of market clearing process to be used in the energy and AS joint market, able to ensure viable and feasible solutions in markets, where there are technical constraints in the transmission network involving its division into areas or regions. The proposed method is based on the determination of Bialek topological factors and considers the contribution of the dispatch for all services of increase of generation (energy, Regulation Up, Spinning and Non-Spinning reserves) in network congestion. The use of Bialek factors in each iteration of the proposed methodology allows limiting the bids in the market while ensuring that the solution is feasible in any context of system operation. Another important contribution of this work is the model of the contribution of distributed energy resources in the ancillary services. In this way, a Virtual Power Player (VPP) is considered in order to aggregate, manage and interact with distributed energy resources. The VPP manages all the agents aggregated, being able to supply AS to the system operator, with the main purpose of participation in electricity market. In order to ensure their participation in the AS, the VPP should have a set of contracts with the agents that include a set of diversified and adapted rules to each kind of distributed resource. All methodologies developed and implemented in this work have been integrated into the MASCEM simulator, which is a simulator based on a multi-agent system that allows to study complex operation of electricity markets. In this way, the developed methodologies allow the simulator to cover more operation contexts of the present and future of the electricity market. In this way, this dissertation offers a huge contribution to the AS market simulation, based on models and mechanisms currently used in several real markets, as well as the introduction of innovative methodologies of market clearing process on the energy and AS joint market. This dissertation presents five case studies; each one consists of multiple scenarios. The first case study illustrates the application of AS market simulation considering several bids of market players. The energy and ancillary services joint market simulation is exposed in the second case study. In the third case study it is developed a comparison between the simulation of the joint market methodology, in which the player bids to the ancillary services is considered by network areas and a reference methodology. The fourth case study presents the simulation of joint market methodology based on Bialek topological distribution factors applied to transmission network with 7 buses managed by a TSO. The last case study presents a joint market model simulation which considers the aggregation of small players to a VPP, as well as complex contracts related to these entities. The case study comprises a distribution network with 33 buses managed by VPP, which comprises several kinds of distributed resources, such as photovoltaic, CHP, fuel cells, wind turbines, biomass, small hydro, municipal solid waste, demand response, and storage units.

Allocation of Parallel Real-Time Tasks in Distributed Multi-core Architectures supported by an FTT-SE Network

Distributed real-time systems such as automotive applications are becoming larger and more complex, thus, requiring the use of more powerful hardware and software architectures. Furthermore, those distributed applications commonly have stringent real-time constraints. This implies that such applications would gain in flexibility if they were parallelized and distributed over the system. In this paper, we consider the problem of allocating fixed-priority fork-join Parallel/Distributed real-time tasks onto distributed multi-core nodes connected through a Flexible Time Triggered Switched Ethernet network. We analyze the system requirements and present a set of formulations based on a constraint programming approach. Constraint programming allows us to express the relations between variables in the form of constraints. Our approach is guaranteed to find a feasible solution, if one exists, in contrast to other approaches based on heuristics. Furthermore, approaches based on constraint programming have shown to obtain solutions for these type of formulations in reasonable time.

Multi-agent simulation of competitive electricity markets: Autonomous systems cooperation for European market modeling

The electricity market restructuring, and its worldwide evolution into regional and even continental scales, along with the increasing necessity for an adequate integration of renewable energy sources, is resulting in a rising complexity in power systems operation. Several power system simulators have been developed in recent years with the purpose of helping operators, regulators, and involved players to understand and deal with this complex and constantly changing environment. The main contribution of this paper is given by the integration of several electricity market and power system models, respecting to the reality of different countries. This integration is done through the development of an upper ontology which integrates the essential concepts necessary to interpret all the available information. The continuous development of Multi-Agent System for Competitive Electricity Markets platform provides the means for the exemplification of the usefulness of this ontology. A case study using the proposed multi-agent platform is presented, considering a scenario based on real data that simulates the European Electricity Market environment, and comparing its performance using different market mechanisms. The main goal is to demonstrate the advantages that the integration of various market models and simulation platforms have for the study of the electricity markets��� evolution.

Grounding in a wind power application

The subject of this master���s thesis is to research grounding in a particular wind power application. The aim is to define how the grounding from different points effects to the function of the whole system. The investigated subjects are generator voltage spikes, ground currents and system fault situations. The first part of this thesis represents power electronics, which is commonly used in wind power systems. The second part concentrates more to the grounding, electrical safety demands and potential fault situations. The object of the simulations is to investigate voltage spikes and fault situations. Measurements will be made with small-scale setup and in the last part simulation and measurement results are compared to each other and to a full-scale system.

Vertailu kahden erityyppisen virtasy��tetyn hakkurin soveltuvuudesta polttokennok��ytt��ihin

Concerns about condition of the environment and rising fossil fuel prices have accelerated the research of finding new cheap and environmental friendly energy source. Fuel cells are one of the most promising green technologies, especially in the field of distributed energy generation, backup power systems, transportation and mobile power generation. In this bachelor���s thesis use of fuel cells is studied, especially from the DC-DC converter point of view. This bachelor���s thesis concentrates on study of two different DC-DC converters. The aim of this thesis is to study design and steering methods for proposed converters. The ultimate aim of this thesis is to determine which one of proposed converters is most suitable for fuel cell applications.

Diskreettiaikainen liukuvan moodin s����t�� kiinte��oksidipolttokennon DC-tasonnostossa

Huoli ymp��rist��n tilasta ja fossiilisten polttoaineiden hinnan nousu ovat vauhdittaneet tutkimusta uusien energial��hteiden l��yt��miseksi. Polttokennot ovat yksi lupaavimmista tekniikoista etenkin hajautetun energiantuotannon, varavoimalaitosten sek�� liikennev��lineiden alueella. Polttokenno on tehonl��hteen�� kuitenkin hyvin ep��ideaalinen, ja se asettaa tehoelektroniikalle lukuisia erityisvaatimuksia. Polttokennon kytkeminen s��hk��verkkoon on tavallisesti toteutettu k��ytt��m��ll�� galvaanisesti erottavaa DC/DC hakkuria sek�� vaihtosuuntaajaa sarjassa. Polttokennon kulumisen est��miseksi tehoelektroniikalta vaaditaan tarkkaa polttokennon l��ht��virran hallintaa. Perinteisesti virran hallinta on toteutettu s����t��m��ll�� hakkurin tulovirtaa PI (Proportional and Integral) tai PID (Proportional, Integral and Derivative) -s����timell��. Hakkurin ep��lineaarisuudesta johtuen t��llainen ratkaisu ei v��ltt��m��tt�� toimi kaukana linearisointipisteest��. Lis��ksi perinteiset s����timet ovat herkki�� mallinnusvirheille. T��ss�� diplomity��ss�� on esitetty polttokennon j��nnitett�� nostavan hakkurin tilayht��l��keskiarvoistusmenetelm����n perustuva malli, sek�� malliin perustuva diskreettiaikainen integroiva liukuvan moodin s����t��. Esitetty s����t�� on luonteeltaan ep��lineaarinen ja se soveltuu ep��lineaaristen ja heikosti tunnettujen j��rjestelmien s����t��miseen.

Chelyabinsk CHP-3 ���locked power��� problem solving

All over the world power systems become bigger and bigger every day. New equipment is installed, new feeders are constructed, new power units are installed. Some old elements of the network, however, are not changed in time. As a result, ���bottlenecks��� for capacity transmission can occur. By locked power problem the situation when a power plant has installed capacity exceeding the power it can actually deliver is usually meant. Regime, scheme or even technical restrictions-related issues usually cause this kind of problem. It is really important, since from the regime point of view it is typical decision to have a mobile capacity reserve, in case of malfunctions. And, what can be even more significant, power plant owner (JSC Fortum in our case) losses his money because of selling less electrical energy. The goal of master`s thesis is to analyze the current state of Chelyabinsk power system and the CHP-3 (Combined Heat and Power plant) in particular in relation with it`s ability to deliver the whole capacity of the CHP in it`s existing state and also taking into consideration the prospect of power unit 3 installation by the fourth quarter of 2010. The thesis contains some general information about the UPS of Russia, CPS of Ural, power system of Chelyabinsk and the Chelyabinsk region itself. Then the CHP-3 is described from technical point of view with it`s equipment observation. Regimes for the nowadays power system and for the system after the power unit 3 installation are reviewed. The problems occurring are described and, finally, a solution is offered.

Working fluid selection and design of small-scale waste heat recovery systems based on organic Rankine cycles

Demand for the use of energy systems, entailing high efficiency as well as availability to harness renewable energy sources, is a key issue in order to tackling the threat of global warming and saving natural resources. Organic Rankine cycle (ORC) technology has been identified as one of the most promising technologies in recovering low-grade heat sources and in harnessing renewable energy sources that cannot be efficiently utilized by means of more conventional power systems. The ORC is based on the working principle of Rankine process, but an organic working fluid is adopted in the cycle instead of steam. This thesis presents numerical and experimental results of the study on the design of small-scale ORCs. Two main applications were selected for the thesis: waste heat re- covery from small-scale diesel engines concentrating on the utilization of the exhaust gas heat and waste heat recovery in large industrial-scale engine power plants considering the utilization of both the high and low temperature heat sources. The main objective of this work was to identify suitable working fluid candidates and to study the process and turbine design methods that can be applied when power plants based on the use of non-conventional working fluids are considered. The computational work included the use of thermodynamic analysis methods and turbine design methods that were based on the use of highly accurate fluid properties. In addition, the design and loss mechanisms in supersonic ORC turbines were studied by means of computational fluid dynamics. The results indicated that the design of ORC is highly influenced by the selection of the working fluid and cycle operational conditions. The results for the turbine designs in- dicated that the working fluid selection should not be based only on the thermodynamic analysis, but requires also considerations on the turbine design. The turbines tend to be fast rotating, entailing small blade heights at the turbine rotor inlet and highly supersonic flow in the turbine flow passages, especially when power systems with low power outputs are designed. The results indicated that the ORC is a potential solution in utilizing waste heat streams both at high and low temperatures and both in micro and larger scale appli- cations.

Kiinteist��automaatio osana ��lykk��it�� s��hk��j��rjestelmi��

Ty��ss�� tarkasteltiin ��lykk��iden s��hk��verkkojen n��k��kulmasta, millaisia toiminnallisuuksia kiinteist��automaatioj��rjestelmilt�� odotetaan ja miten markkinoilla olevat j��rjestelm��t vastaavat n��ihin odotuksiin. Lis��ksi arvioitiin, kuinka taloudellisesti kannattavia valittuihin automaatioj��rjestelmiin kuuluvat energian k��yt��n hallintaan liittyv��t toiminnallisuudet ovat s��hk��nk��ytt��jien n��k��kulmasta. Lopuksi tehtiin lyhyt katsaus kiinteist��automaatioj��rjestelmien tulevaisuuden n��kymiin. Kiinteist��automaatiolla voidaan vaikuttaa energian k��yt��n tehokkuuteen ohjaamalla esimerkiksi valaistusta, ilmanvaihtoa, ilmastointia, l��mmityst�� ja s��hk��laitteita. Er��s vaihtoehto on toteuttaa ohjauksen avulla markkinapohjaista kysynt��joustoa, jossa kiinteist��n s��hk��j��rjestelm��n toimintaa s����det����n s��hk��n hinnan perusteella. Kiinteist��ss�� tulee my��s voida tehd�� laitekohtaisia energiankulutuksen mittauksia, jotka antavat tietoa s��hk��nk��ytt��jille eri laitteiden s��hk��nkulutuksesta. Kiinteist��automaation ja s��hk��n pientuotannon yleistymisen my��t�� on my��s et��hallittavien virtuaalivoimaloiden toteuttaminen tulossa mahdolliseksi. Lis��ksi laskettiin s��hk��nk��ytt��j��n kannalta l��mmityksen, valaistuksen ja ilmanvaihdon ohjauksen kannattavuutta ja selvitettiin, ett�� tutkituissa esimerkkij��rjestelmiss�� suurin s����st��potentiaali on l��mmityksen ohjauksessa.

Assessment of techno-economic use cases for small-scale island grids

The main objective of the study was to define the methodology for assessing the limits for application island grids instead of interconnecting with existing grid infrastructure. The model for simulation of grid extension distance and levelised cost of electricity has been developed and validated by the case study in Finland. Thereafter, sensitivities of the application limits were examined with the respect to operational environment, load conditions, supply security and geographical location. Finally, recommendations for the small-scale rural electrification projects in the market economy environment have been proposed.